linsheng    explained: Metal halide lamps belong to the series of high-intensity discharge (HID) lamps, including mercury vapor lamps and sodium vapor lamps. Like fluorescent lamps, HID lamps generate light by exciting gas confined between a pair of electrodes, and ballasts are needed to limit current consumption and provide appropriate startup and operating voltages. If your metal halide lamp does not start or burns irregularly, there may be a problem with the ballast or bulb. Metal halide bulbs are durable, but they end up being worn.

　　step 1

　　Check the lamp - it may be loose in the socket. If this is the case, please tighten it. If you suspect that the lamp may be burnt out or defective, try replacing the lamp.

　　Step 2

　　Read the ballast specifications on the nameplate, including voltage, power and lamp type, and make sure they match the characteristics of the lamp.

　　Step 3

　　Turn off the circuit breaker that powers the lamp and tighten the connection on the ballast with a screwdriver. If the lamp has never been run, make sure the wiring matches the chart on the ballast label. Make sure the voltage supplied to the ballast is correct. Some ballasts require a 240 volt power supply, powered by two hot wires, each carrying 120 volts and connected to two separate circuit breakers on the panel.

　　Step 4

　　Look inside the ballast for the fuse fuse and replace it with a good fuse. Check the ballast output with a voltage tester. Turn on the lamp, touch the lamp to the lamp electrode, place the lamp in place, then remove the lamp and perform the same test. In both cases, you should obtain a voltage reading that is consistent with the output specified on the label.

　　Step 5

　　Disconnect or turn off all other electrical components on the same circuit as the lamp and try the lamp again. If it is turned on, the circuit may be overloaded.

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